Perimenopause comes with recommendations, so I put magnesium bath salts to the test.

Hot flushes, aching muscles and broken sleep. When a friend recommended magnesium bath salts, I decided to give them six weeks to prove themselves.

Another day, another perimenopause recommendation

There is a side effect of perimenopause that nobody mentions on the official symptom lists: everybody starts recommending things to you. Mention that you’re not sleeping well and somebody knows a supplement. Complain about aching muscles and there’s a powder you should be taking. My bathroom cabinet is beginning to resemble the stockroom of a small branch of Boots, and I’m a lot more suspicious these days of anything promising to transform my life.

I’m 51, perimenopausal and spend a lot of my week punching, kicking, spinning and lifting weights. I love exercise, although my muscles don’t always agree. After complaining about my legs following several Body Pump classes, a friend suggested magnesium bath salts. She swore by them after harder workouts and said they helped her unwind before bed. Magnesium again. It seems to follow us midlifers around. Supplements, sprays, lotions and now something to chuck into the bath, but I decided to put the latest recommendation through The Saffron Experiment to test it for myself.

Could magnesium bath salts help my aching muscles?

I wanted to know whether adding magnesium salts to my bath made any difference to how I felt after exercise, or whether the warm water deserved the credit.

Six weeks with Westlab magnesium bath salts

I bought Westlab Magnesium Replenishing Bath Salts from Tesco and used them once or twice a week for six weeks, usually after Body Pump or demanding cardio sessions. I wasn’t interested in creating laboratory conditions, I just wanted to see whether they’d make any difference to my routine. I ran a warm bath, tipped in a generous handful or two and climbed in for around 20 minutes. There was no measuring jug or expensive spa equipment. Just me, some white crystals and a rare chance to do absolutely nothing.

The salts themselves are pretty plain, there’s no beautiful fragrance or shimmering water like you get with a Lush bath bomb. They just dissolve and disappear. If Cyrus spotted them sitting in a bowl, he’d probably assume we were growing crystals for a school science experiment. Still, I wasn’t buying them for their decorative qualities. I wanted to know whether they’d make the aftermath of a demanding workout more bearable.

Did my aching muscles feel better?

After harder workouts, my legs often felt more comfortable following a bath. That heaviness after Body Pump seemed less noticeable when I’d been a bit ambitious with the squat track. I also felt calmer afterwards and, on some evenings, thought I slept better. I welcomed that because perimenopause has made sleep quite unpredictable. Some nights I’m physically exhausted, but my brain doesn’t realise it’s bedtime.

Before long, I started looking forward to my post-workout bath. The salts became something I reached for instead of another product sitting unused in the bathroom. But there was one important question. Was the magnesium doing anything, or was I just enjoying 20 minutes of peace in warm water?

Can magnesium absorb through your skin?

Magnesium is an essential mineral involved in normal muscle and nerve function. However, that doesn’t automatically mean soaking in magnesium salts allows your body to absorb useful amounts through the skin. A 2017 review of transdermal magnesium found insufficient evidence to support transdermal magnesium as an effective method of supplementation. A 2026 laboratory study examining magnesium movement through pig skin also found minimal permeation across intact skin. Absorption increased when researchers deliberately damaged the skin’s protective barrier.

Neither study proves that magnesium baths can never have benefits. Equally, neither gives me reason to claim that my aching legs improved because I’d absorbed magnesium. The laboratory research wasn’t conducted on people taking baths, and it certainly wasn’t a trial of the Westlab product sitting beside mine. I could describe how I felt afterwards, but I couldn’t explain precisely what caused it.

The bath deserves more credit

Warm bathing has its own evidence behind it. A 2019 review of warm bathing before bed examined research into baths and showers before bedtime. Researchers found that warm water, around one to two hours before sleep, was associated with improved sleep quality and falling asleep more quickly. That doesn’t establish whether my baths improved my sleep, but it offers a plausible explanation that has nothing to do with magnesium.

There’s also the matter of me sitting still. I’m hopeless at doing nothing. I can sit down to watch TV, notice something that needs putting away and somehow end up reorganising a drawer. Even relaxation takes admin these days. A bath puts a stop to that. Nobody expects me to empty the dishwasher while submerged in water, and there’s only so much household management I can accomplish from behind a bathroom door. For 20 minutes, everybody else can manage without my supervision. I may have spent six weeks investigating magnesium only to rediscover the benefits of leaving everyone alone.

Would I buy Westlab magnesium bath salts again?

Yes, although not because I’m convinced the magnesium is working miracles. The salts are easy to use, fragrance-free and have become part of a post-workout routine I genuinely enjoy. My legs often feel more comfortable afterwards, I feel relaxed and sometimes sleep better. Whether that’s down to the minerals, warm water or taking time for myself remains uncertain. My only practical complaint is how quickly the bag empties. A couple of handfuls doesn’t seem excessive until you’ve repeated the process several times.

Westlab Magnesium Replenishing Bath Salts earn four saffron stars. They’re pleasant to use and have earned a place in my routine, although I remain unconvinced by claims about magnesium absorption through the skin. I’ve continued buying them, which probably says more about my experience than any elaborate review could. Would an ordinary warm bath make me feel just as good? Maybe. But I’ve grown fond of my little post-gym ritual, and sometimes that’s reason enough to keep something in the bathroom cupboard.

Have you tried magnesium bath salts for aching muscles or better sleep?

Did you notice a difference, or are we just rediscovering the pleasure of a decent bath?

I bought Westlab Magnesium Replenishing Bath Salts myself from Tesco. This article is not sponsored, and Westlab had no involvement in the experiment or verdict. My experience is personal and should not be taken as evidence that magnesium baths treat perimenopausal symptoms, muscle soreness or magnesium deficiency.

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